HISTOLOGY. 75 



The central nerves are studied by taking a section 

 of the spinal cord and "dissociating the tissue, then 

 scraping the anterior cornua and spreading the ma- 

 terial on a slide and examining it in the fresh state. 

 The best method is to study a stained section and com- 

 pare results with the cuts in all good books on the 

 subject. 



Exercise No. 43. Take a T. $. of the spinal cord of 

 a dog and scrape the anterior cornua, and examine 

 the scrapings. 



Use the saline rnount; search for the following: A 

 large nerve cell having its processes. Locate the axis- 

 cylinder of the cell. 



Exercise No. 44. Examine the nerve of a dog or ox 

 in salt solution. 



Technic same as above. 



Exercise No. 45 Make a T. S. of spinal cord from 

 tissue that has been hardened. Stain, mount and 

 preserve. 



Search for the following: the gray matter, consist- 

 ing of ganglion cells, neuroglia and fibers ; the white 

 matter, consisting of meduHated fibers and connective 

 tissue. 'The white matter surrounds the gray. The gray 



